As a battery with high voltage and high energy density, a Li ion battery is known, for example. The Li ion battery is a cation-based battery utilizing the reaction between a Li ion and a cathode active material and also the reaction between a Li ion and an anode active material. Meanwhile, as an anion-based battery, a fluoride ion battery utilizing a fluoride ion reaction is known.
For example, Patent Literature 1 discloses an electrochemical cell (fluoride ion battery) capable of propagating a cathode, an anode, and an anionic charge carrier (F−). In addition, in Examples of Patent Literature 1, a liquid electrolyte obtained by dissolving LiBF4 in an organic solvent with propylene carbonate (PC) and dimethyl carbonate (DMC) mixed therein is used.